268 Historical 



These are painful and useless calculations; why change a weight 

 into volume to find again a quantity in weight? Let us, however, 

 make them again, because, if their apparent result is favorable, 

 we shall find considerable errors in them. 



A liter of carbonic acid at 0° and 76 cm. of pressure weighs 1.966 



grams. Therefore, 4.51 grams of this gas represent under these 



4.51 

 conditions of temperature and pressure liters, and at 58 cm. 



4.51 liters x 76, 4.51 liters x 76 (273 + 14) 



and at 14° = 3.160 liters. 



1.966 x 58 1.966 x 58 x 273 



So the expired air contained in volume 3.16% of carbonic acid, 

 and not 3.90 as Coindet said, so that all his subsequent results are 

 decidedly wrong. 



Better still: accepting the figure of 3.90% (a proportion, which, 

 by the way, does not vary, as Coindet seems to think, with the 

 pressure and the temperature) we get final results very different 

 from those he records. In fact, the men whom he observed 

 breathed per hour 360 liters of air, which consequently contained, 

 according to him, 360 x 3.9 liters = 14.04 liters of carbonic acid, 

 at 14° and 58 cm., representing at 76 cm. and 0°, 



14.04 liters x 58 x 273 



= 10.19 liters. 



76 (273 + 14) 



Now since 1 liter weighs 1.966 grams, we would have for the 

 production per hour only 1.966 grams x 10.19 = 20.03 grams; and 

 as there is a weight of 27.68% of carbon in carbonic acid, the 

 weight of the carbon consumed per hour would be 



1.966 grams x 10.19 x 27.68 



= 5.54 grams; 



100 * 



which is far from the 12.30 grams announced by Coindet. 



On the contrary, the calculation of M. Jourdanet here finds a 

 complete verification by counter-proof. In fact, it results from 

 what we have just said that really, according to the experiments 

 of Coindet, his men exhaled per hour 



360 liters x 3.16 = 11.376 liters 



of carbonic acid, representing at 76 cm. and 0°, 8.258 liters, which 

 weigh 16.23 grams, a number exactly like the one we found before 

 according to M. Jourdanet. 



